<!-- 核心概览 -- 执行期 -->
<!doctype html>
<html ng-app>
    <head>
        <script src="http://apps.bdimg.com/libs/angular.js/1.4.0-beta.4/angular.min.js"></script>
    </head>
    <body>
        <input ng-model="name">
        <p>Hello {{name}}!</p>
    </body>
</html>